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Fisheries management is often seen as a balancing act that aims for economic development, environmental protection and social development. Previous work shows that overfishing or other forms of poor ecological health, reduces economic profits; and it has long been assumed that pursuit of profits leads to poor social outcomes for fishing communities. But now a new analysis of 121 fisheries worldwide suggests this second assumption may not hold, based on scores of 68 different ecological, economic, and social metrics for each fishery.

Oceanic discoveries of new species continue at pace, with a new species added to the 34,000 previously described: the Polkadot Dwarfgoby (Eviota maculosa). The new species occurs in New Guinea, Indonesia, and Pohnpei in the Federated States of Micronesia, and is distinguished by unique fin patterns, distinctive genetics, and multiple rows of trident-like teeth in both the upper and lower jaws.

Forage fish are small, densely schooling fish at the heart of many marine ecosystems. These fish, including sardines, anchovies, menhaden and their kin, consume tremendous quantities of plankton and also provide abundant food for top marine predators such as larger fish and whales. A key characteristic of these species is their dramatic fluctuation in numbers between high “bonanza” periods and low “collapse” periods, which make them hard to manage.

Tom Quinn and colleagues have found that two decades of carcasses — nearly 600,000 pounds of fish — tossed to the left side of Hansen Creek did have a noticeable effect: White spruce trees on that side of the stream grew faster than their counterparts on the other side.

Captive breeding programs are intended to rebuild highly endangered populations, but a major problem is how to reintroduce captive-bred individuals back to their native habitat. Often, there is low survival of reintroduced individuals compared to wild-born individuals. Such is the case for the critically endangered Vancouver Island marmot, which had shrunk to just 30 individuals in 2003. A new experiment compares survival to breeding age for three strategies: transferring wild-born individuals, translocating captive-born individuals to wild habitat, and a new stepping stone strategy that involved first transplanting captive born individuals to a safe wild area with high survival before transferring them in their second year to the lower-survival final destination.

A new study led by the University of Washington found that although dead whales are still valuable sources of fat and protein for some polar bears, this resource will likely not be enough to sustain most bear populations in the future when the Arctic becomes ice-free in summers, which is likely to occur by 2040 due to climate change. The results were published online Oct. 9 in the journal Frontiers in Ecology and the Environment.

In recent years there has been a growing debate about what proportion of the oceans is fished, with estimates ranging from well above 50% to just 4%. A new paper now looks at one of the most widespread and damaging fishing types, trawling, where a net is dragged over the sea bottom to capture fish. The new method focuses on shallower continental shelves that are less than 1000 m in depth, finding that the trawling footprint varies hugely across regions from 0.4% of the area to more than 80%, with an average of 14% for all regions examined.

A new analysis that uses high-resolution data for 24 ocean regions in Africa, Europe, North and South America and Australasia shows that 14 percent of the overall seafloor shallower than 1,000 meters (3,280 feet) is trawled. Most trawl fishing happens in this depth range along continental shelves and slopes in the world’s oceans. The study focused on this depth range, covering an area of about 7.8 million square kilometers of ocean.

Many fisheries around the world are not formally assessed, and for these fisheries it is hard to know whether they are overfished or not, and how much to fish to ensure that fishing remains sustainable. A suite of models has been developed that can be applied to fisheries where the only data available are time series of catches, but there is no information on trends in actual fish numbers.

Marine fisheries management aims to keep fish populations at sustainable levels while producing seafood. Fisheries that are assessed to be overfished must have their populations rebuilt to sustainable levels by reducing catches to lower levels. Usually the assessment of status relies on a complicated fisheries stock assessment model, sort of like a weather forecast for fisheries, that estimates the level of sustainable catch that can be taken from a fisheries population.